The inventive concept relates to a MOS device having a loop-shaped gate structure. The inventive concept also relates to lateral high voltage transistors such as laterally diffused metal oxide semiconductor (LDMOS) transistors.
In an example of a MOS device, doped regions of a substrate serve as source and drain regions, a loop-shaped gate structure extends around one of the doped regions and is located on the semiconductor substrate between the source and drain regions, and the channel region is a region of the substrate located under the gate structure. Thus, the channel region has linear portions and bend portions. Furthermore, an isolation structure may isolate one of the doped regions. In this case, the gate structure surrounds at least part of the isolations structure. In a laterally diffused metal oxide semiconductor (LDMOS) device, a drift region is provided between the channel region and the drain region.